Read about the latest research published in Psychological Science:
Janna M. Gottwald, Sheila Achermann, Carin Marciszko, Marcus Lindskog, and Gustaf Gredebäck
The authors propose an embodied perspective to early executive-functioning development, suggesting that executive-functioning skills are grounded in infant’s ability to control and plan motor actions. To test this, 18-month-old children completed a simple test of inhibition (avoiding reaching for an attractive toy), a complex test of inhibition (retrieving a toy from a box by inhibiting one action and instead performing a different action), a prospective-motor-control task (reaching for an object and placing it in a wooden box), and a working-memory task (playing a hide-and-seek game). Performance on the prospective-motor-control task was related to performance on the working-memory task and to performance on the simple-inhibition task. These findings support the author’s proposition and demonstrate that motor control is related to executive control early in life.
Yao Zheng, Robert Plomin, and Sophie von Stumm
The two-factor theory of affect suggests that positive affect is primarily influenced by environmental factors, whereas negative affect is primarily dispositional and influenced by personality traits. To test this hypothesis, the researchers examined genetic and environmental influence on day-to-day variability in positive and negative affect in a sample of 17-year-old twins. The twins were assessed for positive and negative affect for 40 days. The researchers found that the average value of negative affect was heritable, but the average value of positive affect showed substantial shared environmental influences. Variations in positive and negative affect were both found to be heritable. These findings support the two-factor theory and also suggest that the degree to which these phenotypes fluctuate may be based on genetics.